Renewing an Old Typewriter Platen

I enjoy rebuilding old typewriters.  I like the challenge of taking something that is 50-100 years old and giving it new life.  One of the challenges in rebuilding an old typewriter is that you can't just log onto the internet and order new parts, since the typewriter industry pretty much died when pc's came on the scene.  So, you either have to cannibalize parts from another old machine, or make them yourself.

One part that you can pretty much never find is a replacement platen.  The rubber on a lot of these old machines dries out and hardens over time, and can develop cracks such as the one in the photo.  This typewriter was made by Remington in 1895, and is one of my current projects.

I won't delve into the details of all the work that has gone into this project -- instead I will focus on how I renewed this old cracked platen.

Step 1: Remove and Measure the Platen

Removing the platen on this old machine was relatively easy.  I removed the knobs on each end, flipped the carriage up (it is an old up-strike machine), and carefully removed the platen assembly.  The first photo shows the platen after removing the knobs and the second photo shows the carriage after the platen came free.

The next step involved carefully measuring the diameter of the platen.  I picked a spot where the rubber was still intact and used a caliper to measure  the diameter.

Step 2: Get the Old Rubber Off of the Core

Using a screwdriver, I carefully prized away the old, hardened rubber.  After removing about half of it, I was able to slip the rest off the end.  Next, I lightly sanded the wooden core, then measured its diameter with the calipers. 

In recovering a platen you pretty much have two choices.  You can try to find an industrial platen rebuilding service and, if they're willing to tackle your job it will cost you roughly $150 -- assuming they have recovering material in the size you need.  This is too pricy for me.

The 2nd choice is to recover it yourself with a piece of smooth rubber hose.  I have had success with this before on small diameter platens, but no one makes a smooth rubber hose in the size I needed. 

So......I decided I needed a 3rd choice.

Step 3: Jumping in With Both Feet -- the 3rd Choice

I decided to reline it with large diameter heat-shrink tubing!  I couldn't find tubing of the diameter I needed locally, but fortunately the internet came to the rescue.

I bought a length of 2" diameter heat-shrink tubing and began the process of building up layers.

Step 4: Building Up the Layers

I cut the first piece of heat-shrink tubing (adding an extra inch in length) and used a heat gun (1st photo) to shrink it to fit the diameter of the core. 

Once it was fitting tightly (2nd photo), I trimmed the ends with a shop knife.  I continued putting layers of the material on the platen and shrinking and trimming them until I had built up to the diameter I needed (this one took 5 layers).  The finished product is in the 3rd photo.

Step 5: Putting It Back Together

Re-installing the platen basically involved doing the initial step in reverse order.  This was the final step in bringing this 118 year old typewriter back to life.  I won't guarantee that it will last another 118 years, but you never know.....